Compression test question

[marklar88]

How long is it necessary to turn the engine over while doing a compression test??? The chiltons manual says 2 or 3 seconds...Does the pressure in the cyliinder keep rising, or is there a max pressure that it will achieve?? Also, what is the compression supposed to be for a 3sgte engine??

[91 Celica St]

DONT KEEP THE DISTRIBUTOR PLUGGED IN, there should be 2 things from your wiering harness goign to the distributor, TAKE THEM OUT...if not youll damage your distributor

pull the spark plugs and skrew in the comp tester, 2-3 seconds wont be long enoghl, keep doing it untill the pressure wont keep rising, it shoudl just kinda jump up and down a little when its at it highest compression (remember to take all 4 spark plugs out before comp testing too)

you sohuld be around 180-200 on the 3sgte

[marklar88]

thanks

[91 Celica St]

so what were your readings?

[marklar88]

Well, they were all really low, all of them between 85 and 110 psi. But maybe that is because we were not turning it over for long enough. I just got a new job(now I can actually fund the mods that I want to do) so I dont have any days off in the forseable future, but I am going to have to do the comp. test again properly and then I will let you know the results, thanks trev

[toyomechanic421]

You should crank it over ten times. You will here it crank slowly and just count ten. Also you must pull your efi fuse so you dont inject any gas into the cylinder. Pull out all the spark plugs, pull your efi fuse, and count ten times for the compression. That is about it.

[marklar88]

well the first two cylinders were 160ish and the 3rd and 4th were 195-205ish..

[91 Celica St]

most lekely u jut need a valve job, the comp on mone of my cylinders was low and all it needed was the vavles to be re shimmed and it came out fine

and you dont need to pull the efi fuse, once the 2 plugs on the D cap are disconnected the ecu automatically realizes theres no spark so it wont give and fuel on a celica

[marklar88]

would malfunctioning valves explain why my engine is overheating and spitting overflowing coolant??

[91 Celica St]

no but a blown headgasket could do those and give you loss of compression